Machine for sharpening knife blades



March 29, 1949. D. B. ELLIG 2,465,678

MACHINE FOR SHARPENING KNIFE BLADES Filed March 19, 1947 Patented Mar.29, 1949 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to knife sharpening machines and while it may beused for sharpening a great variety of knives, it was primarilydeveloped for sharpening ensilage knives. Accordingly, since an ensilageknife sharpening machine is intended for use only during two to fourWeeks a year, or during the harvesting season and stored away the restof the year, it must be made at low costs, because it must be idle mostof the time. nated as well as threaded shafts. The machine is completelyunder the control of the operator at all times as to speed, starting andstopping. No brakes are used and the entire machine is made of steel sothat breakage and repair costs are practically nil.

A motor is employed on the machine to drive the grinding wheel arbor,which motor may of course be employed for other purposes, when thegrinding machine is idle.

For adjusting the knife holder to different widths, and bevels, a guiderod or rail, held in desired height in a slit of about 45 inclination onthe plate is employed. By this means it is possible to move the knifeeasily toward and away from the rotating grinding wheel. The operationmovements are all controlled by the operator thru a hand lever placed atone end of the machine.

These and other objects and advantages will be readily understood fromthe subjoined description, aided by the attached drawing.

Like numerals denote the same details in the difierent views of theinvention.

Figure 1 is a view in front elevation of the machine with a part thereofbroken away;

Figure 2 is a top plan view of the same;

Figure 3 an end view of the machine seen from the right end thereof;

Figure 4 a detail top plan View on an enlarged scale of the knife holderand a part of the actuating mechanism;

Figure 5 is a front view of the knife holder as seen in Figure 4 andFigure 6 shows a side elevation in detail of an adjusting screw and nutfor setting the knife to the desired bevel angle.

Numeral l denotes in general a stand or table needed for carrying allmachinery and is provided with a cooling tank I! thereunder and a motorl2, on a braced support i l at the rear thereof. The grinding or emerywheel l3 with its arbor, is mounted in ball bearings on a bracket l ofmetal in about the middle of the table, preferably welded thereon.

Accordingly, all gear trains are elimi-* The arbor it carries at one enda pulley ll, which runs by a V-belt Ila from the motor I2.

Between two upright bearing plates l8, one erected at each end of thetable I0, is adjustably secured by nuts a guide rod I9 in arcuate slotsI 9a. A knife holder 20 with sleeves 2| engages the rod IQ for slidingback and forth thereon. The knife holder 25] is provided with holes andslots for securing thereon various knives for grinding in the usualmanner. A knife after being secured on the holder 20 is pressed againstthe emery wheel by means of a spring 23 which fits over a stud or post24 and is held compressed by means of a slotted bar 25 which is pivotedon the table. On the stud or post 24 is also hinged a connecting rod 26the outer end of which is pivoted to a handlever 21, hinged at 28 nearthe corner of the table.

The bearing plate I8 for the guide rod I9 is slotted at an angle, about45, so as to move the knife toward, or away from the emery wheel l3, orin other words, the rod [8 and slots I9a provide the means for adjustingthe knife holder 20 for different widths and different bevels of theknife to be ground, whether it is of the ensilage type or the lawnmower, or any similar type.

The guide rod I9 is secured in a fixed position by means of a collar ona bolt 30 engaging the guide rod IS, the pressure being always downwardand away from the emery wheel IS. The bolt 30 passes thru a plate 3|,and has an adjusting nut 32 threaded thereonto bear against the plate3|.

After the knife holder 20 has been set for cutting a desired bevel onthe knife blade, by means of the adjusting nuts 32 and bolts 30 on theguide rod l9, at each end of the machine, there is nothing further toadjust, as the spring 23 holds the knife against the emery wheel I 3with an even pressure along the full length of the blade.

The operator has full control of the machine and the grinding action andis able to run the knife across fast or slow, or stop at one point togrind down a high spot, caused by welding, for instance, by simplyholding the operating handle still a needed length of time.

The following advantages and important features of my invention shouldbe noted:

The machine saves from V; to A; of the time, usually needed forsharpening any kind of bevel edged knives up to 24 inch length and whichcannot be burned on account of continuous application of cooling medium.No special training is required to operate the machine which easily setup and require only one adjustment for each set if knives.

The machine is equipped with a pump for supplying cooling medium fromthe tank II to the emery wheel I3, so that heavy feed, when needed maybe used.

It is to be understood that the invention as herein disclosed may bevaried from the details described and shown without departure from thespirit of the subjoined claims.

I claim:

1. A machine for sharpening knife blades having a straight cutting edge,comprising a working table, a grinding wheel on top thereof, means forrotating the wheel, a knife blade holder, a guide rod having said holdermounted thereon for reciprocatory movement, a bracket at each end of thetable having slanting slots in which the ends of said rod are held andpermitting height and angularity adjustment of the holder carriedthereby in regard to said grinding wheel, and means for reciprocatingthe blade holder along said guide rod.

2. A sharpening machine for knife blades, as described in claim 1,wherein said means for reciprocating the blade holder consists of a handlever hinged on said table near one end of said guide rod, a stud onsaid holder, a slotted swinging bar hinged on said table and having saidstud engage in the slot thereof, and a spring acting between said holderand said bar urging the holder toward said grinding wheel, and linkconnection between said stud and said handlever.

3. A sharpening machine for knife blades as described in claim 1,wherein an arbor is provided for said grinding wheel, the axis of whichis parallel to said guide rod, a pulley on said arbor, an electric motorhaving belt connection 4 with said pulley; a shelf carrying said motoron one side of the table, a brace for said shelf, said operating meansconsisting of a hand lever hinged on said table near one end of saidguide rail, a stud on said holder, a slotted swinging bar hinged on saidtable and having the stud engaged in the slot thereof, a spring actingbetween said holder and said bar urging the holder toward said grindingwheel, and link connection between said stud and said handlever.

4. A sharpening machine for knife blades as described in claim 1,wherein an arbor is provided for said grinding wheel, the axis of whichis parallel to said guide rod, a pulley on said arbor, an electric motorhaving belt connection with 'said pulley, a shelf carrying said motor onone side of the table and a brace for said shelf, said operating meansconsisting of a hand lever hinged on said table near one end of saidguide rail, a stud on said holder, a slotted swinging bar hinged on saidtable and having the stud engaged in the slot thereof, a spring actingbetween said holder and said bar urging the holder toward said grindingwheel, link connection between said stud and said handlever, and acooling tank provided beneath the table.

DONALD B. ELLIG.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS McMillen Mar. 12, 1940

